THIS IS A SHANNON AWARD PROVIDING PARTIAL SUPPORT FOR THE RESEARCH PROJECTS THAT FALL SHORT OF THE ASSIGNED INSTITUTE'S FUNDING RANGE BUT ARE IN THE MARGIN OF EXCELLENCE. THE SHANNON AWARD IS INTENDED TO PROVIDE SUPPORT TO TEST THE FEASIBILITY OF THE APPROACH; DEVELOP FURTHER TESTS AND REFINE RESEARCH TECHNIQUES; PERFORM SECONDARY ANALYSIS OR AVAILABLE DATA SETS; OR CONDUCT DISCRETE PROJECTS THAT CAN DEMONSTRATE THE PI'S RESEARCH CAPABILITIES OR LEND ADDITIONAL WEIGHT TO AN ALREADY MERITORIOUS APPLICATION. THE ABSTRACT BELOW IS TAKEN FROM THE ORIGINAL DOCUMENT SUBMITTED BY THE PRINCIPAL INVESTIGATOR. DESCRIPTION: (adapted from the investigator's abstract) Dr. Levy's long- term research goal is to elucidate the molecular determinants of pathogenesis in lymphoid malignancy. Studies of the molecular basis of lymphoid malignancy demonstrate lesions in genes whose products function normally in the transduction cascade for proliferative and differentiative signals. Her previous studies of oncogenesis in an animal model system demonstrate that two genes, myc and bmi-1, are activated in naturally and experimentally induced thymic lymphomas. Although both myc and bmi-1 have been repeatedly implicated in lymphoid malignancies of various types, their molecular mechanisms of action are not well understood. Evidence indicates that myc encodes a DNA-binding transcriptional regulator, although target genes whose expression is affected by myc have only begun to be identified. Little is known about the function of bmi-1, although its nuclear location and structural hallmarks suggest that it also encodes a DNA-binding protein which may function as a transcriptional regulator. Compelling evidence indicates that myc and bmi-1 collaborate in the malignant process. Dr. Levy proposes to test three hypotheses regarding the role of myc and bmi-1 in malignancy. First, she will test the hypothesis, predicted by its subcellular localization and structural hallmarks, that bmi-1 encodes a DNA-binding protein that may function in regulating transcription. She will examine non-specific DNA binding using DNA-cellulose affinity chromatography, and will also characterize sequence-specific binding. Dr. Levy will test for transcriptional regulation using GAL4( 1 147)- bmi-1 fusion constructs in transient expression assays. Second, they will test the hypothesis that bmi-1 alone or in collaboration with the myc oncogene, plays a significant role in cell transformation. They will determine whether the constitutive overexpression of bmi-1 in early passage fibroblasts is transforming, and whether bmi-1 can cooperate with myc or with ras in co-transformation assays. They will test the further possibility that bmi-1 may cooperate with myc through effects on myc- induced apoptosis. Third, they will examine the hypothesis that pathophysiologically relevant genes can be isolated which are differentially expressed in thymic lymphomas as compared to normal thymus. They will construct a cDNA library from a tumor containing activated myc and bmi- 1, and will isolate genes whose expression is altered in tumors as compared to normal thymus and other relevant tissues. Finally, the locus encoding human bmi- 1 is involved in chromosomal translocations in infant leukemias and T-cell lymphomas. It is not yet known whether the structure or expression of bmi- 1 is affected by the translocation. Dr. Levy proposes to investigate this intriguing possibility. Thus, it is their goal to investigate the function and interaction of two oncogenes shown to be activated during T-cell lymphomagenesis in a model system. The long-term goal is to elucidate the role of oncogene function and cooperation in lymphoid malignancy, with a particular focus on the hypothesis that the deregulation of nuclear regulatory proteins and their targets are pivotal events in the malignant process.